PORT CHARLOTTE, Fla. -- Mike Lowell will take a significant step on Tuesday, when he is expected to make his exhibition debut as the designated hitter in the Red Sox's home game against the Orioles.

For Lowell, it will mark his first game of any kind since Game 3 of Boston's American League Division Series, when he had to shut it down because of ongoing right hip woes. Lowell had surgery on Oct. 20 to repair a torn labrum, and weeks of rehab will pay off when he finally steps back into the batter's box against an opposing pitcher.

If things go as expected, Lowell will start at third base on Friday night against the Yankees.

"If things go according to plan, he will get a couple of at-bats on the 10th as the DH," said Red Sox manager Terry Francona. "I kind of reserve the right to change this. But then we have a night game, three days later, maybe he'll play third base then. That's what he's shooting for. Our medical people don't seem to have a problem with it."

In other injury related news, right-hander Brad Penny will throw a 35-pitch side session before Sunday's game. No date has been set for Penny's exhibition debut.

Francona isn't sure if outfielder Rocco Baldelli will return to the lineup on Sunday. The right-handed hitter has been experiencing some stiffness in his groin.

"I really didn't want to push that," Francona said. "And I haven't talked to him yet this morning. It's been the last couple of days. It wasn't real bad early. I just kind of thought it made sense to stay away until he's not feeling it. I know there's times during the season where everybody feels it. I just don't think [playing through] it down here makes a lot of sense."